There are certain articles and more especially flat self-supporting articles such as CDs that need to be printed upon, on both sides thereof. For reasons of cost the endeavour is for the articles to be printed upon, at both sides, in one pass through the machine. That however generally presupposes that, after printing or decoration of some other kind has been applied to the articles on one side thereof, the articles are turned so that the second side thereof is made accessible to the printing units and possibly also other treatment units, for example driers or the like.